Odd Subject on BT mobile

[TheSeasider]

I have a VERY OLD motorola V3i & Fancied using it .. (It is / was) on the old Orange network  Now I assumed (Wrongly) that I could swop out my SIM to the old V3i & As BT USE THE EE NETWORK (That WAS Orange) .. it would function normally ... IT WONT 

Its asking for a "Subsidiary Code" ... WHAT THE HELL IS ONE OF THEM ??? 

Any Help from Tech or Guru's would be of great help !! 

Cheers guys 

Keith 

[NigelB72]

I doubt it'll work because the Motorola is only 2G (GSM) 

[TheSeasider]

I'm on to Orange  ...................................We live in HOPE Nige ... We LIVE IN HOPE matey LOL!!!